This document summarizes several novel drug delivery systems targeted for colon delivery. It describes systems such as pressure-controlled drug delivery systems which use capsule thickness and peristalsis to control drug release. It also discusses pH-dependent systems like CODESTM that protect the drug in the stomach and small intestine before bacteria trigger release in the colon. Timed-release systems are explained like OROS-CT which uses osmotic pressure to precisely control release over hours. Other systems presented include pulsincap, hydrophilic capsules, and technologies like Targit, Egalet, and Enterion capsules that aim to topically target drug release in the colon.

1. Recent Advances in Colon
Targeted Drug Delivery Systems
Presented by-
Sulabh Singhania
M.Pharm – 2nd SEM
DEPARTMENT OF PHARMACEUTICS
Enrollment No-201504100410019

2. Novel Advancements in CDDS
 PCDCS.
 CODESTM.
 OROS – CT.
 Pulsincap system.
 Port system.
 Time clock system.
 Hydrophilic sandwich
capsule.
 Chronotropic system.
 Colal – Pred system.
 Targit technology.
 Egalet technology.
 Enterion capsule
technology.
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3. Pressure-Controlled Drug-Delivery Systems
(PCDDS)
• Lag time of 3-5 hrs is noted.
• Driving force-Peristalsis.
• Drug release occurs following disintegration of a water-
insoluble polymer capsule as a result of pressure.
• Thickness of the membrane, capsule size and density plays a
crucial role in release.
• Drug delivered should be in liquid state to facilitate absorption
as lumen content is already viscous.
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4. CODESTM
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5. CODESTM
• CODESTM is a combined approach of pH dependent and
microbially triggered CDDS.
• The premise of the technology is that the enteric coating
protects the tablet while it is located in the stomach and then
dissolves quickly following gastric emptying.
• The acid soluble material coating then protects the
preparation as it passes through the alkaline pH of the small
intestine.
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6. CODESTM
• Once the tablet arrives in the colon, the bacteria
enzymatically the polysaccharide (lactulose) into organic acid.
• This lowers the pH surrounding the system sufficient to effect
the dissolution of the acid soluble coating and subsequent
drug release.
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7. Osmotic Controlled Drug Delivery
(OROS-CT)
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8. (OROS-CT)
• The OROS-CT system can be a single osmotic unit or may
incorporate as many as 5-6 push-pull units, each 4 mm in
diameter, encapsulated within a hard gelatin capsule.
• Each bilayer push pull unit contains an osmotic push layer and
a drug layer, both surrounded by a semi permeable
membrane.
• An orifice(6.35µm) is drilled through the membrane next to
the drug layer
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9. (OROS-CT)
• Upon swelling the gelatin capsule dissolves.
• Drug impermeable enteric coating of push pull units prevent it
from absorbing water in acidic environment.
• Upon entering small intestine the coating dissolves whereby,
allowing absorption of water, causing the osmotic push
compartment to swell concomitantly creates a flow-able gel in
the drug compartment
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10. (OROS-CT)
• Swelling of the osmotic push compartment forces drug gel out
of the orifice at a rate precisely controlled by the rate of
water transport through the semi permeable membrane
• Materials used as
– semi permeable materials- cellulose acylate, or cellulose
acetate
– Osmopolymers- PVA, PVP
– Enteric coating materials- pthalates bases.
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11. PULSINCAP System
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12. PULSINCAP System
• It comprises of a water-insoluble capsule enclosing the drug
reservoir.
• A swellable hydrogel plug was used to seal the drug contents
into the capsule body.
• When this capsule came in contact with the dissolution fluid,
it swelled; and after a lag time, the plug pushed itself outside
the capsule and rapidly released the drug.
• The length of the plug and its point of insertion into the
capsule controlled the lag time.
– Polymers for hydrogels –HPMC, PVA, PEO, PMA
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13. Hydrophilic sandwich capsule
• It is simply a capsule in capsule.
• Within which the intracellular space is filled with hydrophilic
polymer, which created a hydrophilic sandwich between two
capsules.
• When the outer shell dissolved the hydrophilic polymer
provided a time delay before the fluid could enter the inner
capsule and cause drug release.
• The time delay was controlled by the molecular weight of the
polymers and it can also be further manipulated.
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14. PORT system
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15. PORT system
• It consists of a capsule coated with a semipermeable
membrane.
• Inside the capsule was an insoluble plug(made up of waxes,
fatty easters) consisting of osmotically active agent( mannitol,
sorbitol etc,) and the drug formulation.
• The increased pressure due to swelling of osmogen forces the
plug to slide out of the shell to release the drug.
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16. TIMECLOCK system
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17. TIMECLOCK system
• Based on solid dosage form that is coated by an aqueous
dispersion.
• This coating is a hydrophobic surfactant layer to which a
water soluble polymer is added to improve adhesion to the
core.
• Upon contact with the dissolution fluid the dispersion
rehydrates and redisperses.
• The lag time could be controlled by varying the thickness of
the film. After the lag time, i.e; the time required for
rehydration, the core immediately releases the drug.
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18. TARGITTM
• It is developed to deliver drugs for the topical treatment of
the colonic diseases.
• The technology is based on the application of pH- Sensitive
coatings onto injection-moulded starch capsules.
• An extensive body of clinical data has been generated
showing reliable in vivo performance of the capsules.
• TARGIT based products are in active clinical development for
the treatment of conditions including inflammatory bowel
diseases.
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19. Chronotropic system
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20. Chronotropic system
• These systems are based upon a drug reservoir surrounded
with a soluble barrier layer that dissolves with time and the
drug releases at once after this lag time.
• Chronotropic system consists of a core containing reservoir
coated by a hydrophilic polymer HPMC.
• An additional enteric-coated film is given outside this layer to
overcome intra subject variability in gastric emptying rates
• The lag time and the onset of action are controlled by the
thickness and the viscosity grade of HPMC.
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21. Enterion capsule Technology
• Long, round-ended capsule and contains a drug reservoir with
a volume capacity of approximately 1 ml.
• The capsule can be loaded with either a liquid formulation
through an opening 9 mm in diameter, which is then sealed by
inserting a push-on Cap fitted with a silicone O-ring.
• A radioactive marker is placed inside a separate sealed tracer
port to allow real time visualization of the capsule location
using the imaging technique of gamma Scintigraphy.
• Upon reaching the target site in GI tract, the contents are
actively ejected by the external application of an oscillating
magnetic field.
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22. COLALTM
• COLAL-PRED has a coating that is broken down only in the
colon, by locally occurring bacteria.
• COLAL-PRED is a proprietary gastrointestinal product
developed by alizyme for the treatment of ulcerative colitis
(US).
• This leads to topical delivery of prednisolone to the colon
without significant systemic exposure so minimizing steroid
related side effects.
• It is ethyl-cellulose and amylase film coating based system, in
which amylase works in pore forming agent and EC act as
release control matrix agent via swelling or enzyametic
degradation.
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23. EGALET TECHNOLOGY
• It offers two systems the constant release 2K system and
delayed release 3K system.
• The 2K system consists of two compartments: an
impermeable coat and matrix.
• The drug is distributed throughout the matrix and it release
the drug as it passes through the gut.
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24. EGALET TECHNOLOGY
• The 3K comprises of impermeable shell and two lag plugs.
• Enclosing the active drug into two lags.
• The active drug releases after the lags are removed causing a
delay in the drug release.
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25. References
• K.V. Vinaykumar et al. “Colon targeting drug delivery system:
A review on recent approaches. Int J Pharm Biomed Sci 2011.
• R.J. Michael et al. modified release drug delivery system,
informa healthcare volume 1 second edition P.No. 287-356.
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26. THANK YOU
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